1. Field of Invention
The present invention relates to a method for manufacturing an inkjet recording medium.
2. Description of the Related Art
Recently, various information processing systems have been developed along with rapid development in the Information Technology (IT) industry, and recording methods and recording devices suitable for respective information processing systems have also been developed and practically used. Among these, an inkjet recording method has been broadly used because it has such advantages that images are recordable on various kinds of recording materials, hard wares (devices) for the inkjet recording method can be manufactured at a comparatively low cost and made compact as well, excellent stillness can be provided, and the like. The latest inkjet recording method can provide so-called “picture like” high quality images.
The recording materials for inkjet recording have been generally required to have properties such as (1) quick drying (high ink absorption speed), (2) ink dots having proper and uniform diameters (no bleeding), (3) excellent granularity, (4) high circularity of dots, (5) high color density, (6) high color saturation (no dullness), (7) excellent water proof, light fastness, and ozone proof at an imaging area, (8) high degree of whiteness, (9) excellent storability of a recording medium (no occurrence of yellow discoloration or image bleeding during long term storage), (10) low deformability and excellent dimensional stability (low curling properties) or (11) excellent running properties in hardware.
In view of the above, in recent years, inkjet recording media (inkjet recording materials) having an ink receiving layer with a porous structure have been put into practical use, and various studies have been made thereof.
For example, to suppress coating defects and obtain good ink absorbability, a technique is known in which an ink receiving layer is formed by performing a first coating step wherein a first coating liquid containing a crosslinking agent is coated on a substrate, and a second coating step wherein a second coating liquid containing inorganic fine particles and a binder is coated thereon, wherein the second coating liquid is crosslinked and cured on the layer formed by the first step, at the same stage of coating the first coating liquid in the first step, or before the first coating liquid coated in the first step is dried and cured (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2004-230599).
In order to improve ink absorptivity, glossiness and printing density, a technique is known in which at least two ink receiving layers are provided on a water-resistant support: an ink receiving layer (A) which is provided closer to the water-resistant support and which contains vapor-phase-process silica, boric acid or borate, and polyvinyl alcohol with a polymerization degree of less than 3,000; and an ink receiving layer (B), which is provided further from the water-resistant substrate and which contains an alumina or an alumina hydrate, boric acid or borate, and polyvinyl alcohol with a polymerization degree of 3,000 or more (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2002-225423).
Further, in order to obtain high glossiness with photo-like quality and high ink absorptivity, and to improve indoor image storability, a technique is known in which an ink receiving layer includes polymer compounds having a structure with a thiourea group, particularly, a polyamine with a thiourea group (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-203010).
It is also known that in a system in which a pseudo boehmite alumina hydrate, a water-soluble binder and a crosslinking agent are contained, aggregation tends to occur, and coating defects such as cracks are apt to arise. Accordingly, both of high printing density and suppression of coating defects cannot always be achieved by using only the techniques disclosed above.